Disease outbreaks in horses refer to the occurrence and spread of infectious diseases within equine populations. These outbreaks can be caused by various pathogens, including bacteria, viruses, and parasites, and can lead to significant health issues in affected horses. Common diseases that may result in outbreaks include equine influenza, equine herpesvirus, strangles, and equine infectious anemia. The transmission of these diseases can occur through direct contact, environmental exposure, or vectors such as insects. Disease outbreaks can have substantial impacts on horse health, welfare, and the equine industry as a whole. This page compiles peer-reviewed research studies and scholarly articles that explore the epidemiology, transmission dynamics, and management strategies associated with disease outbreaks in equine populations.
Episodic collapse in horses has equine welfare and human safety implications. There are, however, no published case series describing this syndrome. Objective: To characterize the cause and outcomes for horses referred for investigation of episodic collapse. Methods: Twenty-five horses referred for investigation of single or multiple episodes of collapse. Methods: Retrospective study. Clinical records from the Dick Vet Equine Hospital, University of Edinburgh from November 1995 to July 2009 were searched using the following keywords: collapse, collapsing, fall, syncope. Collapse was defined as...
Equine coronavirus (ECoV) leads to outbreaks with variable morbidity and mortality. Few previous reports of risk factors for infection are available in the literature. Unassigned: To describe unique clinical findings and risk factors for infection and development of clinical disease. Unassigned: 135 horses on a farm affected by ECoV outbreak. Unassigned: Retrospective cohort study. Data obtained included age, breed, gender, activity level, housing, and feed at the onset of the outbreak. Factors were evaluated for assessment of risk of infection using simple logistic regression or Fisher's exac...
The results of integrated human and veterinary surveillance for West Nile virus (WNV) infections in Austria during the transmission seasons 2015 and 2016 are shown. Altogether WNV nucleic acid was detected in 21 humans, horses, wild birds and mosquito pools. In detail: in four human clinical cases [two cases of West Nile fever (WNF) and two cases of West Nile neuroinvasive disease (WNND)]; eight blood donors [among 145,541 tested donations], of which three remained asymptomatic and five subsequently developed mild WNF; two horses with WNND, of which one recovered and one had to be euthanized; ...
There is a paucity of information regarding the association between common disorders and outcome over time in a large population of ill equine neonates. Objective: To describe the relative frequency of neonatal disorders in a large population of foals admitted to a neonatal intensive care unit, to determine the disorders and factors associated with nonsurvival and determine if the outcome of ill neonatal foals has improved over time. Methods: Retrospective study. Methods: Cases were selected from equine neonatal (≤14 days of age) admissions between 1982 and 2008. Multivariable logistic regre...
Tau RL, Marandino AE, Panzera Y, Alamos F, Vissani MA, Romera SA, Pérez R, Maidana SS.The Equid alphaherpesvirus type 1 (EHV-1) infection can have devastating economic consequences in the horse industry due to large-scale outbreaks of abortions, perinatal foal mortality, and myeloencephalopathy. The present study analyzed the genome of two isolates obtained from aborted fetuses in Argentina, E/745/99 and E/1297/07. The E745/99 genome shares 98.2% sequence identity with Ab4, a reference EHV-1 strain. The E/1297/07 genome shares 99.8% identity with NY03, a recombinant strain containing part of ORF64 and part of the intergenic region from Equid alphaherpesvirus-4 (EHV-4). The E/12...
Sévin C, Duquesne F, Copin S, Raguenet V, Guy M, Wilhelm A, Gassilloud B, Moreau P, Petry S.A retrospective review of equine necropsies performed at the Normandy Laboratory for Animal Health, French Agency for food, environmental and occupational health and safety (1996-2022) unexpectedly reported Vibrio alginolyticus, Vibrio parahaemolyticus and Vibrio vulnificus in equine samples using API 20NE, prompting a re-evaluation of bacterial identification. Of 27 strains, 25 were cultivable, and re-examined using API 20NE, API 20E, MALDI-TOF, 16S rRNA gene sequencing and Vibrio-specific PCR assays. API 20NE confirmed the original (erroneous) identifications; all Vibrio-specific PCR assays ...
Fukumoto N, Shibata M, Hayashi M, Kawauchi K, Yabuuchi Y, Oue Y, Matsuyama R, Yamamoto T, Mita H, Kawanishi N, Bannai H, Tsujimura K, Yamanaka T....In 2025, an outbreak of equine influenza occurred among draft horses at Obihiro Racecourse in Hokkaido, Japan. The number of horses showing clinical signs increased dramatically in April. The proportion affected was significantly higher in 2-year-olds than in older groups. The proportion that developed fever during the outbreak was significantly higher than that observed among Thoroughbreds during the 2007 outbreak. In non-epidemic periods, the geometric mean hemagglutination inhibition antibody titer of 2-year-old draft horses was significantly lower than that of 2-year-old Thoroughbreds. The...
Aguirre Siliezar K, Datu C, Proia K, Rotstein D, Nemser SM, Tyson GH, Ragsdale JM, Wilkes RP, Baker RE, Carossino M, Del Piero F, Sasaki E, Yant P....A multi-state outbreak of equine botulism occurred between December 2022 and March 2023 in the United States. Follow-up and testing were performed on 42 horses, including 24 that died or were euthanized in the outbreak that affected ~98 horses. Affected horses had all been exposed to the same commercial feed. Clinical signs included progressive muscle weakness and tremors, recumbency, and colic. No significant gross or microscopic abnormalities were observed on autopsy. Feces and gastrointestinal content were tested for various infectious agents, including botulinum toxin; fecal samples from 2...